Answer:
25 because the 8 values must times with 7 and will get 56. when the ninth value added , let the ninth value as y , 56+y , the new mean is 9 . so it will be like this , 56+y over 9 times with 9
85
Step-by-step explanation:
Write the numbers in order
66, 72, 74, 80, 83, 87, 91, 95, 98, 99
Find the middle number
83 and 87 are in the middle, so find the mean of them. 83+87= 170
170/2 = 85.
5x+2y=20
Substitute 0.3 for x
5(0.3)+2y=20
Multiply 5 by 0.3
1.5+2y=20
Subtract 1.5 from both sides
2y=18.5
Divide 2 on both sides
Final Answer: y= 9.25
25.2